Resolvin D1 (RvD1), an endogenous pro-resolving mediator of inflammation, is derived from omega-3 docosahexaenoic acid during the resolution phase of acute inflammation. Resolvin D1 blocks proinflammatory neutrophil migration by regulating actin polymerization, reduces TNF-α–mediated inflammation in macrophages, and enhances phagocytosis of apoptotic cells by macrophages[2].In Vitro: Resolvin D1 (RvD1) (1-100 nM; 15 minutes) induces dose-dependent short-term functional changes in primary human macrophages. RvD1 triggers intracellular Ca2+ release, blocks chemotactic migration, and stimulates phagocytosis of microbial particles with maximal efficiency at 10 nM.Resolvin D1 (0-500?nM; 72 hours) shows a strong inhibition of LPS-induced TRAP and cathepsin K expression by RvD1 at different concentrations in RAW264.7 macrophages[2].In Vivo: Resolvin D1 (RvD1) (100-1000 ng; i.p.; daily on days 10) improves RA (rheumatoid arthritis) clinical endpoints in arthritic mice.